VERTEBRAL COUNT AS A MERISTIC CHARACTER OF TWO NILE CHARCOID FISHES ALESTES NURSE AND ALESTES BAREMOSE

Document Type : Research article

Authors

Abstract

Assiut samples of Alestes nurse revealed sexual dimorphism as regards their total ver tebral counts, whereas Aswan ones did not. The total vertebral counts of Asslut com bined sex samples of A.nurse did not vary from year to year. Variation of the total vertebral counts of Assiut and Aswan samples of A.nurse was mainly due to the varia tion of abdominal vertebral counts; variation in caudal vertebral counts had little contribution in this respect. The total, abdominal and caudal vertebral counts revealed that Assiot and Aswan combined sex samples of A.nurse represented geographical races and not a subspecific status. The total vertebral count proved to be reliable for the differentiation between A.nurse and A.baremose since they were widely different and did not vary according to the total length.